The instant invention relates to an electrical power outlet and more particularly to a female power outlet arranged to become energized only when a male matching power plug is fully inserted therein.
It is well known that electrical power outlets can cause fires or injuries when metallic objects are accidentally inserted thereto, as may happen for example when children insert wires and other objects into the openings of the outlet provided for receiving the prongs of a matching power plug.
It is also well known to provide matching plugs and outlets that are arranged such that an electrical connection is not established until the male and female parts are joined and airtight, to avoid explosion and fire danger in case the plug and outlet are joined with power connected. U.S. Pat. No. 2,697,212 shows such an explosion-proof connecting device. Other constructions are known from the prior art that provide explosion proof connections in various ways.
The devices of the prior art, however, suffer from the drawback that they do not prevent accidental insertion of wires or metals from causing injury or fires because none of them insure that all power is removed from the outlet until the mating plug and outlet are completely joined together. The prior art devices also have the drawback that specially constructed mating plugs and outlets must be provided. This, clearly, is a disadvantage since so many electrical appliances are now provided with standard plugs, that it would be impractical to change them all in order to accomodate a new specially constructed outlet.